Starter for an internal combustion engine

ABSTRACT

An internal combustion engine starter having a high starting performance has a first cranking mechanism including a self-starting motor 13 and a second cranking mechanism including a kick lever 18. The second cranking mechanism causes a crankshaft 1 to rotate mechanically during the beginning of its rotation which requires a high torque, and the first cranking mechanism places it in continuous rotation.

TECHNICAL FIELD

This invention relates to a starter for the internal combustion engineof, for example, a two-wheeled motor vehicle.

BACKGROUND ART

A starter for the internal combustion engine of a two-wheeled motorvehicle is shown in FIG. 1 to illustrate a conventionally known internalcombustion engine starter of the type to which this invention pertains.The engine has a crankshaft 1 to which a sprocket 2 is secured. Anintermediate shaft 3 lies in parallel to the crankshaft 1 and isrotatably supported by a bearing 4 on a stationary member not shown. Asprocket 5 is connected to the intermediate shaft 3 by a rotationalvariation buffering mechanism not shown. The sprocket 5 is connected tothe sprocket 2 by a chain 6.

An overrunning clutch 7 has an outer member 7a to which the sprocket 5is secured, and an inner member 7b fitted about the intermediate shaft3. A sleeve 8 is disposed between the shaft 3 and the inner member 7bwhich are rotatable relative to each other. A spur gear 7c is formed onthe inner member 7b. A spur gear 9 is secured to the intermediate shaft3. A large gear 10 meshes with the spur gear 9 and is connected to aspeed change gear not shown by a clutch not shown. An intermediate gear11 is secured to a rotary shaft 12 and meshes with the spur gear 7c. Aself-starting motor 13, which is driven by a battery 15 upon closure ofa self-starting switch 14, has an output shaft 13a on which a pinion 16meshing with the intermediate gear 11 is secured. A lever shaft 17 hasat one end a clutch portion 17a which engages it unidirectionally withthe rotary shaft 12. A kick lever 18 is connected to the other end ofthe lever shaft 17. The sprockets 2 and 5, chain 6, overrunning clutch7, intermediate gear 11, rotary shaft 12, pinion 16, self-starting motor13, self-starting switch 14 and battery 15 form a first crankingmechanism. The sprockets 2 and 5, chain 6, overrunning clutch 7,intermediate gear 11, rotary shaft 12, lever shaft 17 and kick lever 18form a second cranking mechanism which is manually operable.

The manual cranking mechanism makes it possible to start the enginemechanically as will hereinafter be described. The kick lever 18 isactuated to rotate the lever shaft 17 and its rotation is transmitted tothe crankshaft 1 through the rotary shaft 12, intermediate gear 11,overrunning clutch 7, sprocket 5, chain 6 and sprocket 2, whereby theengine is started. The rotation of the engine is transmitted to thespeed change gear through the sprocket 2, chain 6, sprocket 5,rotational variation buffering mechanism, intermediate shaft 3, spurgear 9, large gear 10 and the clutch not shown. The overrunning clutch 7prevents the reverse motion of the kick lever 18, etc.

The cranking mechanism including the self-starting motor 13 enables theelectrical starting of the engine as will hereinafter be described. Theself-starting switch 14 is closed to supply electric current from thebattery 15 to the self-starting motor 13 and thereby cause it to rotate.The rotation of the output shaft 13a is transmitted to the crankshaft 1through the pinion 16, intermediate gear 11, overrunning clutch 7,sprocket 5, chain 6 and sprocket 2, whereby the engine is started. Theunidirectional engagement of the clutch portion 17a prevents the reverserotation of the kick lever 18 and the lever shaft 17. The rotation ofthe engine is transmitted to the speed change gear as hereinabovedescribed.

The kick lever 18 and the lever shaft 17 have, however, their ownstructural limitations which disable them to rotate beyond a certainangle to cause the crankshaft 1 to rotate continuously. An internalcombustion engine having a large displacement capacity is particularlydifficult to start by the cranking mechanism including the kick lever18. The cranking mechanism including the kick lever 18 and the crankingmechanism including the self-starting motor 13 are, therefore, bothprovided for some internal combustion engines of large displacementcapacity for two-wheeled motor vehicles, as shown in FIG. 1. A hightorque is required for causing the crankshaft 1 to rotate, especiallywhen starting its rotation. The battery 15 in a two-wheeled motorvehicle has a relatively small capacity due to a limited space availablefor its installation. It is rapidly consumed, since it is freuquentlyused to start the engine. A reduction in the voltage supplied from thebattery makes it more difficult to start the engine quickly.

DISCLOSURE OF THE INVENTION

It is an object of this invention to improve the drawbacks of theconventional apparatus as hereinabove pointed out and provide aninternal combustion engine starter having a high starting performanceobtained by first causing the second cranking mechanism to rotate thecrankshaft mechanically and then causing the first cranking mechanismincluding a self-starting motor to place the crankshaft in continuousrotation.

According to this invention, the crankshaft is mechanically rotated bythe second cranking mechanism during the beginning of its rotation whichrequires a high torque, and is subsequently placed in continuousrotation by the first cranking mechanism including the self-startingmotor. It has only a reasonable amount of battery consumption and can beused to start the engine easily even after a reduction in the voltagesupplied from the battery. It is, therefore, an apparatus of greatlyimproved starting performance and reliability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view, partly in section, of a conventionalapparatus;

FIG. 2 is a side elevational view, partly in section, of an apparatusembodying this invention;

FIG. 3 is a front elevational view of the cam 19 and microswitch 20shown in FIG. 2; and

FIG. 4 is a circuit diagram for the apparatus of this invention.

FIG. 5 is a circuit diagram for an alternate embodiment of the presentinvention.

BEST MODE OF CARRYING OUT THE INVENTION

An apparatus embodying this invention is shown in FIGS. 2 to 4. Likenumerals are used to indicate like parts throughout FIG. 1 and FIGS. 2to 4. Referring to FIGS. 2 to 4, a disk-shaped cam 19 is secured to thelever shaft 17 and a microswitch 20 having a lever 20a contacting theouter periphery of the cam 19 is connected in parallel to theself-starting switch 14. The cam 19 and the microswitch 20 define ameans for driving the self-starting motor. The apparatus of thisinvention is identical to the conventional apparatus in all the otheraspects of construction and no further description thereof will,therefore, be made.

In operation, the kick lever 18 is actuated to cause the crankingmechanism including the kick lever 18 to rotate the crankshaft 1mechanically as hereinbefore described in connection with theconventional apparatus. At the same time, the cam 19 is rotated in thedirection of an arrow to its position shown by a broken line in FIG. 3to close the microswitch 20. An electric current is, therefore, suppliedto the self-starting motor 13 to actuate the cranking mechanismincluding the motor 13 so that the crankshaft 1 which has been urged torotate by the actuation of the kick lever 18 is placed in continuousrotation, whereby the engine is started. As the self-starting motor 13is operated during the rotation of the crankshaft 1 by the kick lever18, a relatively low torque is sufficient to place the crankshaft 1 incontinuous rotation and does not cause any large consumption of thebattery 15. After the engine has been started, the kick lever 18 isreleased from pressure, and a return spring not shown brings it back toits original position and thereby returns the cam 19 to its positionshown by a solid line in FIG. 3, whereby the microswitch 20 is opened todiscontinue the operation of the self-starting motor 13. It is alsopossible to actuate only the cranking mechanism including theself-starting motor 13 by closing the self-starting switch 14.

Although the self-starting motor driving means hereinabove describedcomprises the cam 19 and the microswitch 20, it is equally possible toemploy a means of different construction comprising, for example, amicroswitch for detecting the rotation of the kick lever 18 and a timerresponsive to its output for supplying an electric current to theself-starting motor 13 for a predetermined length of time. FIG. 5 showsschematically a modified circuit diagram from that of FIG. 4 in whichlike elements have like numerical designations and wherein the contactor20 is closed to apply a voltage from source 15 for predetermined periodof time as defined by countdown of counter 22 which is well known per seand which controls the flow of current to coil 23 for opening thenormally closed contacts of contactor 24. As a result electric currentflow to the starter motor 13 is terminated.

It is also possible to provide a path for electric current to theself-starting motor 13 with a motor protecting device which opens itscontacts upon detecting the start of the engine. This arrangement iseffective for improving the reliability of the apparatus to a furtherextent.

Although the foregoing description has been based on the internalcombustion engine of a two-wheeled motor vehicle provided with thecranking mechanism including the kick lever 18 and the crankingmechanism including the self-starting motor 13, this invention is, ofcourse, applicable to an internal combustion engine of any other type,too, for example, one for an outboard which is provided with a crackingmechanism including a recoil starter and a cranking mechanism includinga self-starting motor.

Although the first and second cracking mechanisms have been described assharing certain mechanical connecting parts from the sprockets 2 and 5to the rotary shaft 12 for the intermediate gear 11, it is, of course,possible to construct those two mechanisms completely independently ofeach other.

INDUSTRIAL UTILITY

This invention is applicable not only to a starter for the internalcombustion engine of a two-wheeled motor vehicle or an outboard, butalso to a starter for an internal combustion engine of any other type.

I claim:
 1. A starter for an internal combustion engine comprising afirst cranking mechanism including a self-starting motor for causing anengine crankshaft to rotate electrically, a second mechanical crankingmechanism for causing said crankshaft to rotate mechanically and meansfor detecting the operation of said second mechanical cranking mechanismfor a predetermined time to effect initial rotation of said crankshaftto a predetermined extent for delayed energizing said self-startingmotor, so that said motor may place said crankshaft in continuousrotation only after said second cranking mechanism has caused it toinitially rotate.
 2. A starter for an internal combustion enginecomprising a first cranking mechanism including a self-starting motorfor causing an engine crank shaft to rotate electrically, a secondmechanical cranking mechanism for causing said crank shaft to rotatemechanically and means for detecting the operation of said secondmechanical cranking mechanism for a predetermined time to effect initialrotation of the crank shaft to a predetermined extent for delayedenergizing said self-starting motor so that the motor may place saidcrank shaft in continuous rotation only after the second crankingmechanism has caused it to initially rotate, and wherein said secondmechanical mechanism comprises a kick lever, said first crankingmechanism comprises a cam secured to said kick lever and a microswitchcontrolling electric current flow to said self-starting motor having alever contacting the outer periphery of said cam.
 3. A starter for aninternal combustion engine as set forth in claim 1, wherein said secondmechanical cranking mechanism comprises a kick lever, said firstcranking mechanism comprises a microswitch controlling electric currentflow to said self-starting motor for detecting the rotation of said kicklever and a time responsive to the closure of said microswitch forsupplying an electric current to said self-starting motor for apredetermined length of time.
 4. A starter for an internal combustionengine as set forth in claim 1, wherein said second cranking mechanismincludes a recoil starter.